1. Field of the Invention
The present invention relates to an image forming system for forming an image on an image-forming sheet, coated with a layer of micro-capsules filled with dye or ink, by selectively breaking or squashing the micro-capsules in the layer of micro-capsules. Further, the present invention relates to such an image-forming sheet and an image-forming apparatus, which forms an image on the image-forming sheet, used in the image-forming system.
2. Description of the Related Art
An image-forming system per se is known, and uses an image-forming sheet coated with a layer of micro-capsules filled with dye or ink, on which an image is formed by selectively breaking or squashing micro-capsules in the layer of micro-capsules.
For example, in a conventional image-forming system using an image-forming sheet coated with a layer of micro-capsules in which a shell of each micro-capsule is formed from a photo-setting resin, an optical image is formed as a latent image on the layer of micro-capsules by exposing it to light rays in accordance with image-pixels signals. Then, the latent image is developed by exerting pressure on the layer of micro-capsules. Namely, the micro-capsules, which are not exposed to the light rays, are broken and squashed, whereby dye or ink seeps out of the broken and squashed micro-capsules, and thus the latent image is visually developed by the seepage of dye or ink.
Of course, in this conventional image-forming system, each of the image-forming sheets must be packed so as to be protected from being exposed to light, resulting in wastage of materials. Further, the image-forming sheet must be handled such that they are not subjected to excess pressure due to the softness of unexposed micro-capsules, resulting in an undesired seepage of dye or ink.
Also, a color-image forming system, using an image-forming sheet coated with a layer of micro-capsules filled with different color dye or ink, is known. In this system, the respective different colors are selectively developed on an image-forming sheet by applying specific temperatures to the layer of color micro-capsules. Nevertheless, it is necessary to fix a developed color by irradiation, using light of a specific wavelength. Accordingly, this color-image-forming system is costly, as an additional irradiation apparatus for the fixing of a developed color is needed, and electric power consumption is increased due to the additional irradiation apparatus. Also, since a heating process for the color development and an irradiation process for the fixing of a developed color must be carried out with respect to each color, hinder a quick formation of a color image on the color-image-forming sheet is hindered.